Debugged the collision detection code in cyphesis, sorted
out the problem with created entities inheriting bounding
boxes from the creator, and made an attempt at handling
two moving entities colliding.

Added Structure base class for buildings or other server
entities that the player can move into. Modified collision
rules so that if an entity collides with a structure
bounding box, the entity move into that structure, making
it possible to move in and out of buildings.

Started work on a simple library for rendering building
blocks using the off screen Mesa GL library.

Loading of terrain info into the client must be
separated from loading of entity information, as the two
are not that closely related, and the server must be able
to get full information about the pre-defined entities in
the world, which it currently cannot do from the terrain
map format.